scholarly journals Novel Findings From Family-based Exome Sequencing for Children With Biliary Atresia

Author(s):  
Kien Tran ◽  
Vinh Le ◽  
Lan Dao ◽  
Huyen Nguyen ◽  
Anh Mai ◽  
...  

Abstract Biliary atresia (BA) is a progressive inflammation and fibrosis of the biliary tree, characterized by the obstruction of bile flow led to liver failure, scarring and cirrhosis. This study aimed to explore the elusive etiology of BA by conducting whole exome sequencing (WES) for 41 children with BA and their parents (35 trios, including one family with two BA diagnosed children and five child-mother cases). We exclusively identified and validated a total of 28 variants (17 X-linked, six de novo and five homozygous) in 25 candidate genes from our BA cohort. These variants were among the 10% most deleterious and having a low minor allele frequency against three employed databases: Kinh Vietnamese (KHV), gnomad and 1000 Genome project. Interestingly, AMER1, INVS and OCRL variants were repeatedly found in unrelated probands, and were firstly reported in a BA cohort. Liver specimens and blood samples showed identical variants, suggesting that somatic mutations were unlikely to occur during the morphogenesis. In agreement with earlier attempts, this study implicated a genetical heterogeneity and non-Mendelian inheritance of BA.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kien Trung Tran ◽  
Vinh Sy Le ◽  
Lan Thi Mai Dao ◽  
Huyen Khanh Nguyen ◽  
Anh Kieu Mai ◽  
...  

AbstractBiliary atresia (BA) is a progressive inflammation and fibrosis of the biliary tree characterized by the obstruction of bile flow, which results in liver failure, scarring and cirrhosis. This study aimed to explore the elusive aetiology of BA by conducting whole exome sequencing for 41 children with BA and their parents (35 trios, including 1 family with 2 BA-diagnosed children and 5 child-mother cases). We exclusively identified and validated a total of 28 variants (17 X-linked, 6 de novo and 5 homozygous) in 25 candidate genes from our BA cohort. These variants were among the 10% most deleterious and had a low minor allele frequency against the employed databases: Kinh Vietnamese (KHV), GnomAD and 1000 Genome Project. Interestingly, AMER1, INVS and OCRL variants were found in unrelated probands and were first reported in a BA cohort. Liver specimens and blood samples showed identical variants, suggesting that somatic variants were unlikely to occur during morphogenesis. Consistent with earlier attempts, this study implicated genetic heterogeneity and non-Mendelian inheritance of BA.


PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253562
Author(s):  
Evie Kritioti ◽  
Athina Theodosiou ◽  
Thibaud Parpaite ◽  
Angelos Alexandrou ◽  
Nayia Nicolaou ◽  
...  

Multiple malformation syndromes (MMS) belong to a group of genetic disorders characterised by neurodevelopmental anomalies and congenital malformations. Here we explore for the first time the genetic aetiology of MMS using whole-exome sequencing (WES) in undiagnosed patients from the Greek-Cypriot population after prior extensive diagnostics workup including karyotype and array-CGH. A total of 100 individuals (37 affected), from 32 families were recruited and family-based WES was applied to detect causative single-nucleotide variants (SNVs) and indels. A genetic diagnosis was reported for 16 MMS patients (43.2%), with 10/17 (58.8%) of the findings being novel. All autosomal dominant findings occurred de novo. Functional studies were also performed to elucidate the molecular mechanism relevant to the abnormal phenotypes, in cases where the clinical significance of the findings was unclear. The 17 variants identified in our cohort were located in 14 genes (PCNT, UBE3A, KAT6A, SPR, POMGNT1, PIEZO2, PXDN, KDM6A, PHIP, HECW2, TFAP2A, CNOT3, AGTPBP1 and GAMT). This study has highlighted the efficacy of WES through the high detection rate (43.2%) achieved for a challenging category of undiagnosed patients with MMS compared to other conventional diagnostic testing methods (10–20% for array-CGH and ~3% for G-banding karyotype analysis). As a result, family-based WES could potentially be considered as a first-tier cost effective diagnostic test for patients with MMS that facilitates better patient management, prognosis and offer accurate recurrence risks to the families.


2017 ◽  
Vol 41 (S1) ◽  
pp. S309-S309 ◽  
Author(s):  
H. Yoo ◽  
S.A. Kim ◽  
M. Park ◽  
J. Kim ◽  
W.J. Lim ◽  
...  

ObjectivesThe objective of this family-based whole exome sequencing (WES) is to examine genetic variants of autism spectrum disorder (ASD) in Korean population.MethodsThe probands with ASD and their biological parents were recruited in this study. We ascertained diagnosis based on DSM-5™ criteria, using Autism Diagnostic Observation Schedule and Autism Diagnostic Interview–Revised. We selected probands with typical phenotypes of ASD both in social interaction/communication and repetitive behaviour/limited interest domains, with intellectual disability (IQ < 70), for attaining homogeneity of the phenotypes. First, we performed WES minimum 50× for 13 probands and high-coverage pooled sequencing for their parents. We performed additional WES for 38 trio families, at least 100× depth. De novo mutations were confirmed by Sanger sequencing. All the sequence reads were mapped onto the human reference genome (hg19 without Y chromosome). Bioinformatics analyses were performed by BWA-MEM, Picard, GATK, and snpEff for variant annotation. We selected de novo mutation candidates from probands, which are neither detected in two pooled samples nor both parents.ResultsFifty-one subjects with ASD (5 females, 40∼175 months, mean IQ 42) and their families were included in this study. We discovered 109 de novo variants from 46 families. Twenty-nine variants are expected to be amino acid changing, potentially causing deleterious effects. We assume CELSR3, MYH1, ATXN1, IDUA, NFKB1, and C4A/C4B may have adverse effect on central nerve system.ConclusionsWe observed novel de novo variants which are assumed to contribute to development of ASD with typical phenotypes and low intelligence in WES study.Disclosure of interestThis work has been supported by Healthcare Technology R&D project (No: A120029) by Ministry of Health and Welfare, Republic of Korea.


2019 ◽  
Author(s):  
Ramakrishnan Rajagopalan ◽  
Ellen A. Tsai ◽  
Christopher M. Grochowski ◽  
Susan M. Kelly ◽  
Kathleen M. Loomes ◽  
...  

AbstractBiliary atresia (BA) is a severe pediatric liver disease resulting in necroinflammatory obliteration of the extrahepatic biliary tree. BA presents within the first few months of life as either an isolated finding or with additional syndromic features. The etiology of isolated BA is unknown, with evidence for infectious, environmental, and genetic risk factors described. However, to date, there are no definitive causal genes identified for isolated BA in humans, and the question of whether single gene defects play a major role remains open. We performed exome-sequencing in 100 North American patients of European descent with isolated BA (including 30 parent-child trios) and considered several experimental designs to identify potentially deleterious protein-altering variants that may be involved in the disease. In a case-only analysis, we did not identify genes with variants shared among more than two probands, and burden tests of rare variants using a case-case control design did not yield significant results. In the trio analysis of 30 simplex families (patient and parent trios), we identified 66 de novo variants in 66 genes including a nonsense variant, p.(Cys30Ter), in the gene STIP1. STIP1 is a co-chaperone for the heat-shock protein, HSP90AA1, and has been shown to have diverse functions in yeast, flies and mammals, including stress-response.ConclusionOur results do not support the hypothesis that a simple genetic model is responsible for the majority of cases of isolated BA. Our finding of a de novo mutation in a candidate gene for BA (STIP1) linked to evolutionarily conserved stress responses suggests further exploration of how genetic susceptibility and environmental exposure interact to cause BA is warranted.


2020 ◽  
Vol 16 ◽  
pp. 117693432095657
Author(s):  
Saowwapark Chanwigoon ◽  
Sakkayaphab Piwluang ◽  
Duangdao Wichadakul

The detection of copy number variations (CNVs) on whole-exome sequencing (WES) represents a cost-effective technique for the study of genetic variants. This approach, however, has encountered an obstacle with high false-positive rates due to biases from exome sequencing capture kits and GC contents. Although plenty of CNV detection tools have been developed, they do not perform well with all types of CNVs. In addition, most tools lack features of genetic annotation, CNV visualization, and flexible installation, requiring users to put much effort into CNV interpretation. Here, we present “inCNV,” a web-based application that can accept multiple CNV-tool results, then integrate and prioritize them with user-friendly interfaces. This application helps users analyze the importance of called CNVs by generating CNV annotations from Ensembl, Database of Genomic Variants (DGV), ClinVar, and Online Mendelian Inheritance in Man (OMIM). Moreover, users can select and export CNVs of interest including their flanking sequences for primer design and experimental verification. We demonstrated how inCNV could help users filter and narrow down the called CNVs to a potentially novel CNV, a common CNV within a group of samples of the same disease, or a de novo CNV of a sample within the same family. Besides, we have provided in CNV as a docker image for ease of installation ( https://github.com/saowwapark/inCNV ).


2020 ◽  
Author(s):  
Wai-Yee Lam ◽  
Man-Ting So ◽  
Jacob Shujui Hsu ◽  
Patrick Ho-Yu Chung ◽  
Diem Ngoc Ngo ◽  
...  

ABSTRACTBiliary atresia (BA) is the most common obstructive cholangiopathy in neonates, often progressing to end-stage cirrhosis. BA pathogenesis is believed to be multifactorial, but the genetic contribution remains poorly defined. We conducted exome sequencing on 89 nonsyndromic BA trios. In 31.5% of the patients, rare and deleterious de novo, homozygous recessive and/or compound heterozygous variants were detected in liver-expressed ciliary genes of diverse ciliary functions. Enrichment of deleterious mutations in liver-expressed ciliary geneset was significant compared to 148 control trios (OR 2.58, 95% CI 1.15-6.07). KIF3B, PCNT and TTC17 are essential for ciliogenesis. Reduced ciliary proteins expression were detected in the BA livers with KIF3B and TTC17 mutations. CRISPR/Cas9-engineered zebrafish knockouts of KIF3B, PCNT and TTC17 displayed reduced biliary flow. Our findings support a larger genetic contribution to nonsyndromic BA risk than expected. Ciliary gene mutations leading to cholangiocyte cilia malformation and dysfunction could be a key biological mechanism in BA pathogenesis.


Author(s):  
Adam L. Numis ◽  
Gilberto da Gente ◽  
Elliott H. Sherr ◽  
Hannah C. Glass

Abstract Background The contribution of pathogenic gene variants with development of epilepsy after acute symptomatic neonatal seizures is not known. Methods Case–control study of 20 trios in children with a history of acute symptomatic neonatal seizures: 10 with and 10 without post-neonatal epilepsy. We performed whole-exome sequencing (WES) and identified pathogenic de novo, transmitted, and non-transmitted variants from established and candidate epilepsy association genes and correlated prevalence of these variants with epilepsy outcomes. We performed a sensitivity analysis with genes associated with coronary artery disease (CAD). We analyzed variants throughout the exome to evaluate for differential enrichment of functional properties using exploratory KEGG searches. Results Querying 200 established and candidate epilepsy genes, pathogenic variants were identified in 5 children with post-neonatal epilepsy yet in only 1 child without subsequent epilepsy. There was no difference in the number of trios with non-transmitted pathogenic variants in epilepsy or CAD genes. An exploratory KEGG analysis demonstrated a relative enrichment in cell death pathways in children without subsequent epilepsy. Conclusions In this pilot study, children with epilepsy after acute symptomatic neonatal seizures had a higher prevalence of coding variants with a targeted epilepsy gene sequencing analysis compared to those patients without subsequent epilepsy. Impact We performed whole-exome sequencing (WES) in 20 trios, including 10 children with epilepsy and 10 without epilepsy, both after acute symptomatic neonatal seizures. Children with post-neonatal epilepsy had a higher burden of pathogenic variants in epilepsy-associated genes compared to those without post-neonatal epilepsy. Future studies evaluating this association may lead to a better understanding of the risk of epilepsy after acute symptomatic neonatal seizures and elucidate molecular pathways that are dysregulated after brain injury and implicated in epileptogenesis.


2021 ◽  
Vol 2 (1) ◽  
pp. 100383
Author(s):  
Nicholas S. Diab ◽  
Spencer King ◽  
Weilai Dong ◽  
Garrett Allington ◽  
Amar Sheth ◽  
...  

Genes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 65
Author(s):  
Patricia Haug ◽  
Samuel Koller ◽  
Jordi Maggi ◽  
Elena Lang ◽  
Silke Feil ◽  
...  

Coloboma and microphthalmia (C/M) are related congenital eye malformations, which can cause significant visual impairment. Molecular diagnosis is challenging as the genes associated to date with C/M account for only a small percentage of cases. Overall, the genetic cause remains unknown in up to 80% of patients. High throughput DNA sequencing technologies, including whole-exome sequencing (WES), are therefore a useful and efficient tool for genetic screening and identification of new mutations and novel genes in C/M. In this study, we analyzed the DNA of 19 patients with C/M from 15 unrelated families using singleton WES and data analysis for 307 genes of interest. We identified seven novel and one recurrent potentially disease-causing variants in CRIM1, CHD7, FAT1, PTCH1, PUF60, BRPF1, and TGFB2 in 47% of our families, three of which occurred de novo. The detection rate in patients with ocular and extraocular manifestations (67%) was higher than in patients with an isolated ocular phenotype (46%). Our study highlights the significant genetic heterogeneity in C/M cohorts and emphasizes the diagnostic power of WES for the screening of patients and families with C/M.


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